1. Biosolids, Manure, and Micronutrients
Robert Mullen & Nick Basta
Nutrient Management/Soil Fertility Specialist
Ohio State University
February 21, 2008

2. Overview Essential micronutrients
Deficiency/toxicity
Biosolids/manure micronutrient content
Micronutrient soil availability
11/15/2018
MWEA 2008

3. Essential Nutrients Thirteen essential nutrients
Nitrogen, phosphorus, potassium, calcium, magnesium, sulfur (macros)
Iron, manganese, boron, molybdenum, copper, zinc, and chlorine (micros)
Nickel has recently been added
Micros are needed in much lower concentrations to ensure adequate supply
11/15/2018
MWEA 2008

4. Plant concentration, mg/kg
Essential Nutrients
Necessary micronutrient concentrations for plant growth
Nutrient
Plant concentration, mg/kg
Iron
50-200
Manganese 20
Boron
10-50
Chlorine
100
Zinc
20-50
Copper
Molybdenum
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MWEA 2008

5. Essential Nutrients
Micronutrients can be toxic when supplied at levels higher than plant nutrient need
University of Hawaii
11/15/2018
MWEA 2008

6. Biosolids/Manures
It stands to reason that human and animal waste contain the macro-/micronutrients needed for higher plant nutrition
Everything we consume is plant based
Thus, logically any animal waste material likely contains some level of micronutrient nutrition
11/15/2018
MWEA 2008

7. ----------------mg/kg-----------------
Biosolids/Manures
Typical biosolid micronutrient content
Nutrient
Range
Median
Mean
mg/kg
Iron
1, ,000
11,000
13,000
Manganese
18-7,100
260
380
Boron
4-760 33 77
Zinc
101-27,800
1740
2790
Copper
84-10,400
850
1210
Molybdenum
5-39 30 28
Sommers (1997) – Journal of Environmental Quality 6:
11/15/2018
MWEA 2008

8. Biosolids/Manures
Average animal manure micronutrient content of different animal sources
Manure source
Iron
Manganese
Boron
Zinc
Copper
lb/wet ton
Dairy solid
0.5
0.06
0.01
0.03
Swine solid
19.0
1.09
0.04
0.79
0.50
Poultry
3.0
0.61
0.08
0.48
0.66
lb/1000 gal
Dairy liquid
0.9
0.11
0.12
Swine liquid
2.5
0.23
1.03
0.62
Micronutrient Status of Manure, University of Wisconsin, 2001
11/15/2018
MWEA 2008

9. Biosolids/Manures
Biosolids/manures can be good sources of plant essential micronutrients
Let’s calculate just how much we add based upon a single application rate
11/15/2018
MWEA 2008

10. Application rate (lb/acre)
Biosolids/Manures
Suppose we are applying 3 tons of biosolids per acre (dry basis), how much iron, manganese, boron, zinc, copper, and molybdenum have we supplied?
Nutrient
Application rate (lb/acre)
Iron 78
Manganese
2.3
Boron
0.5
Zinc
16.8
Copper
7.3
Molybdenum
0.2
11/15/2018
MWEA 2008

11. Biosolids/Manure
Do not assume that application will necessarily result in higher plant uptakes
We have ample evidence that shows levels will increase if the nutrient was deficient
But non-deficient sites will not necessarily show increases in crop uptake
11/15/2018
MWEA 2008

12. Biosolids/Manure
Remember, biosolids/manure do not supply a salt form analogous to commercial forms
Availability may not necessarily be comparable to commercial forms (at least short-term)
Predicated on biosolid/manure application rate
11/15/2018
MWEA 2008

13. Biosolids/Manure Application rates and availability
Long-term application of biosolids (13 years) on micronutrient availability (DTPA extractable)
Study conducted at Oklahoma State University
Biosolids application rate ranged from 3,500 – 10,000 lbs/acre (depending upon nitrogen analysis of material)
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MWEA 2008

14. Biosolids/Manure Total micronutrient analysis of soil PAN rate (kg/ha)Fe B Cu Zn
mg/kg
Biosolids
25.4
0.53
1.23
0.77 45
34.7
0.36
2.10
2.00 90
31.0
0.58
2.30
2.27
180
55.0
0.44
5.60
7.17
269
58.6
0.60
7.13
9.77
539
92.5
0.80
11.0
15.5
Ammonium nitrate
31.5
0.52
1.43
43.8
0.56
1.63
1.07
60.9
0.33
1.60
57.1
0.32
1.67
63.4
0.26
1.83
0.73
Schroeder et al. (2008) Soil Science Society of America Journal 72:73-82.
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MWEA 2008

15. Micronutrient Soil Availability
Even though we may be supplementing micronutrient nutrition through biosolid/manure application their availability is dictated by soil pH
More of a concern as it relates to toxicity from long-term application of biosolids/manures
11/15/2018
MWEA 2008

16. Micronutrient Availability
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MWEA 2008

17. Micronutrient Availability
More acid soils have better (?) micronutrient availability (this goes for most of the heavy metals)
Exception being molybdenum
More acid soils also have greater risk of micronutrient toxicity (especially if the soil has a history of biosolids/manure applications)
11/15/2018
MWEA 2008

18. Micronutrient Availability
To minimize risk of toxicity maintain soil pH in optimum range for crop production ( )
Soils that have high soil pH levels are more likely to exhibit micronutrient deficiencies, thus application of biosolids/manure on these soils can be very beneficial
11/15/2018
MWEA 2008

19. Summary
Biosolids/manure can be excellent sources of micronutrient nutrition for higher plants
Soils with application histories can show higher micronutrient availability levels than those receiving commercial fertilization
Maintaining adequate soil pH for crop production should ensure good micronutrient availability
11/15/2018
MWEA 2008

20. Questions?? Thanks! http://agcrops.osu.edu/fertility/ Robert W. Mullen
11/15/2018
MWEA 2008